content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * -----------------------------
   * PieSectionLabelGenerator.java
   * -----------------------------
   * (C) Copyright 2001-2008, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 13-Dec-2001 : Version 1 (DG);
   * 16-Jan-2002 : Completed Javadocs (DG);
   * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
   * 30-Oct-2002 : Category is now a Comparable instance (DG);
   * 07-Mar-2003 : Changed to KeyedValuesDataset and added pieIndex
   *               parameter (DG);
   * 21-Mar-2003 : Updated Javadocs (DG);
   * 24-Apr-2003 : Switched around PieDataset and KeyedValuesDataset (DG);
   * 13-Aug-2003 : Added clone() method (DG);
   * 19-Aug-2003 : Renamed PieToolTipGenerator --> PieItemLabelGenerator (DG);
   * 11-Nov-2003 : Removed clone() method (DG);
   * 30-Jan-2004 : Added generateSectionLabel() method (DG);
   * 15-Apr-2004 : Moved generateToolTip() method into separate interface and
   *               renamed this interface PieSectionLabelGenerator (DG);
   *
   */
  
  package org.jfree.chart.labels;
  
  import java.awt.Font;
  import java.awt.Paint;
  import java.awt.font.TextAttribute;
  import java.text.AttributedString;
  
  import org.jfree.data.general.PieDataset;
  
  /**
   * Interface for a label generator for plots that use data from
   * a {@link PieDataset}.
   */
  public interface PieSectionLabelGenerator {
  
      /**
       * Generates a label for a pie section.
       *
       * @param dataset  the dataset (<code>null</code> not permitted).
       * @param key  the section key (<code>null</code> not permitted).
       *
       * @return The label (possibly <code>null</code>).
       */
      public String generateSectionLabel(PieDataset dataset, Comparable key);
  
      /**
       * Generates an attributed label for the specified series, or
       * <code>null</code> if no attributed label is available (in which case,
       * the string returned by
       * {@link #generateSectionLabel(PieDataset, Comparable)} will
       * provide the fallback).  Only certain attributes are recognised by the
       * code that ultimately displays the labels:
       * <ul>
       * <li>{@link TextAttribute#FONT}: will set the font;</li>
       * <li>{@link TextAttribute#POSTURE}: a value of
       *     {@link TextAttribute#POSTURE_OBLIQUE} will add {@link Font#ITALIC} to
       *     the current font;</li>
       * <li>{@link TextAttribute#WEIGHT}: a value of
       *     {@link TextAttribute#WEIGHT_BOLD} will add {@link Font#BOLD} to the
       *     current font;</li>
       * <li>{@link TextAttribute#FOREGROUND}: this will set the {@link Paint}
       *     for the current</li>
       * <li>{@link TextAttribute#SUPERSCRIPT}: the values
       *     {@link TextAttribute#SUPERSCRIPT_SUB} and
       *     {@link TextAttribute#SUPERSCRIPT_SUPER} are recognised.</li>
       * </ul>
       *
       * @param dataset  the dataset.
       * @param key  the key.
       *
       * @return An attributed label (possibly <code>null</code>).
       */
      public AttributedString generateAttributedSectionLabel(PieDataset dataset,
                                                             Comparable key);
  
  }
  